Collapsible connecting rod



16 1940., F. A. KucaRA coLLAPsIBLE coNNEcTING Rop 2 Sheets-Sheet 1 Filed June 22, 1937 FIG-f.

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Patented Apr. 16, 1940 I COLLAPSIBLE CONNECTING ROD Frank A. Kucera, Chicago, Ill., assignor to Union f Special Machine Company, Chicago, Ill., a corporation of Illinois Application June 22, 1937, Serial No.' 149,6110 9 Claims. (Cl. 'I4-579) This invention relates to connecting rods having components which are connected by a pivot or knuckle joint so that the rod may be collapsed or buckled. Such a rodV is useful for example,

with looper mechanism of sewing machines as exemplified in U. S. Patent No. 1,850,949, granted to Clarence C. Smith on March 22, 1932.

One of the aims of my invention vis to insure against the development of looseness between the components of a connecting rod. of the sort referred to and so prevent rattling during the operation of the rod, and at the same time to render the rod rigid against the possibility of ,accidental collapse either under endwise tension or compression in use.

Another object of my invention is to limit the extent of angular movement of the components incident to collapsing of the rod, and to provide for the maintenance of the rod yieldingly in collapsed position with capacity for being easily and quickly extended by exertion of, slight lateral pressure thereupon at the region of pivoting of its components.

One way inr which the foregoing and other objects and advantages can be readily realized in practice is clearly set forth in the following detailed description of the attached drawings, wherein Fig. I is a fragmentary view'in longitudinal section of a chain stitch sewing machine with looper mechanism incorporating the connecting rod of my invention. I

Fig. II is a view like Fig. I showing the connecting rod in collapsed condition. v

Fig. III is a fragmentary view on an enlarged scale, partly in side elevation and partly in longitudinal section, showing the rod in its normal condition. e

Fig. IV is a detail illustration Viewed as indicated by the arrows IV-IV in Fig. III,Va portion of the rod having been broken away for exposure of important parts at the interior. e I

Fig. V is a view corresponding to Fig. III but with the rod collapsed. l

Figs. VI and VII are perspective views respectively of the pivot ends of the rod components. Y

In Figs. I and II of these illustrations, `my irnproved collapsible rod is designated comprehensively by the numeral I and shown asserving in the capacity of a link between a carrier 2 for the looper 3 of a sewing machine Aand a bell crank member ll. The looper 3 cooperates with the needle 5 of the sewing machine beneath the bed plate or work support 6 ofthe latter in a well known way to produce stitches, the looper carrier 2 being fulcrumed at 'l on asleeve 8.which latter issecured to a horizontal shaft 9 jornaled for oscillation in pendant bearing lugsL l of the work Support 6. The bell crank member 4 is afxedfto'a transverse -rock shaft I`I,.and has its horizontal arm l2 connected, by means of a pitman i3, with an actuating crank I4 on a drive shaft i5 which extends longitudinally beneath the'work support-6 of the machine. yAs presently explained, the connecting rod lis so constructed that it may be collapsed as shown in. Fig. II to eli'ect retraction ofthe looper 3 from the pathof the needle 5 and soi render itconveniently 'accessible fory threading. y

Referring now more particularly to Figs.' III-VII, it will be observed thatthefconnecting rod of my invention'comprises two main com- Ponents I6 and l1, each of which is in turni of f composite construction.` As shown, the 'component lhas an'outer end member. Iii-With a split bearing 19 adapted, in the presentinstance, to receive the ball head 2l! of a stud on. the looper carrier 2; a cylindric inner end member?! V(separately illustrated in perspective in Fig. VI) with a clevi'sed hefad 22,and with an intermediate por-y tion,23 in vthe form' 'of a screw whereof the opposite ends are i'eversely threaded and engage into the contiguous ends of vsaid end portions i8 and 2`I. By turning'the screw member `23 in one direction orthe other, thecomponent I6 Amay be lengthened and `shortened as may be desired or required, said screw member ,beingprovided with a polygonalcollar 24 for convenience of adl site'sides'of the endmember 2 I, is secured to said bolt. As shown, the bolt 28 is subject to a helical compression spring 33 which tends to urge it outward of the cavity 27 in the end member 2| of the component I6. g f

The component l'l of the rod likewise has an outer end member 35 with asplit bearing 35 forv engaging, in this instance, the ball of ay stud .3l on the member 4 of a sewing' machine; and anA inner end-member 38 (separately illustrated in Fig. VIlI) fitting with a` ilat head 39 within `the clevised head 22 of the contiguous endmember 2l rofthecomponentul, and. a screwshank lil axially engaged in the .end member 35. By virtue of v`this construction, vthe rod component. I1 canv liliv be shortened or lengthened like the component IB as desired or required, a jam nut 4l being relied upon to fix the parts in adjusted positions.

A pin 42 extending crosswise of the rod through registering transverse apertures in the interlapping portions of the members 22 and 38 serves to pivotally unite the components I6 and I1, said pin being held in place in the member 38 by a set screw shown at 43. Extending inward from the square endiace 45 of the member 38 'is a socket 4S which is tapered to correspond with the tapered end 29 of the bolt 28 and which is adapted to receive said bolt as shownin Fig. III.

Under the pressure of the spring 33, a snug Wedging interengagement is maintained between the tapered end of the bolt 28 and the socket 45 With the result that the development of looseness between the interpivoted rod components I6 and H is denitely precluded and rattling of the bar during operation of the sewing machine avoided; The bolt 28 moreover acts as a means to positively lock the components I6 and l1 in direct axiall alignment so that they rod cannot accidentally collapse or buckle in use. Upon Withdrawing the bolt 28 from the socket 46 of the component Vl by manipulating the slide collai` 3B, the rod can be collapsed as shown in Fig. V by pressing upon the same from above at the region of the pivot 42, in which condition it will be yieldingly maintained through coaction of the tapered end 2Q of the bolt 28 with a curved camming surface l1 on the head 39 of the end member 38 vof the component Il. The extent of rela' tive angular movement between the components 5 and Il in the collapse of the rod is limited as shown in Fig. V through engagement of lateral stud projections t8 on the member 38 of the component il with stop lugs 49 formed on the head 22 of the member 2l of the component IB. Restoration of the rod to its normal condition is effected by slight upward pressure at the region of the pivot 42 incident to which the bolt 28 will ride the curved cam surface 131 and finally be forced into the-socket 46 by the spring 33 automatically.

In cases Where lengthwise adjustment of the rod is not important or essential, the components I6 and Il may be integrally formed respectively insteadof being of multipartite construction as herein shown and described. It is of course to be understood that the use of my improved collapsible connecting rod is not intended to be restricted to sewing machines.

Having thus described my invention, I claim: l.` A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends for connection respectively to an actuator and'to an element to be actuated; a pivot interconnecting ythe contiguous ends of the rod components; means for locking the rod against collapse in its normal condition including a bolt which is conned to longitudinal sliding movement on one of said components and which is adapted to engage a socket in the other component and means associated with one of said components for automatically holding the bolt retracted when the rod is collapsed, and for controlling the bolt to cause it to automatically relock the components when the latter are brought into alignment from collapsed condition.

2. A collapsible connectingrodcomprisingapair of lengthwise adjustable components which are normally aligned axially and which have pivots at their remote ends for connection respectively vto an actuator and to an element to be actuated;

a pivot interconnecting the contiguous ends of the rod components; means for locking the rod against collapse in its normal condition including a bolt which is coniined to longitudinal sliding movement on one of said components and which is adapted to engage a socket in the other component and means associated with one of said components for automatically holding the bolt retracted When the rod is collapsed, and for controlling the bolt to cause it to automatically relock the components when the latter are brought into alignment from collapsed condition.

3. A collapsible connecting rod comprising a pair of components which are normally aligned axially, and which have pivots at their remote ends for connection respectively to an actuator and to an element to be actuated; a pivot intern connecting the contiguous ends of the rod components; means for locking the rod against collapse in its normal extended condition including a bolt which is conned to longitudinal sliding movement on one of the components, and which has a tapered end adapted to engage a correspondingly tapered socket in the other component with a wedge t and means associated with one of said components for automatically holding the bolt retracted When the rod is collapsed, and for controlling the bolt to cause it to automatically relock the components when the latter are brought into alignment from collapsed condition.

4. A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends for connection respectively to an actuator and to an element to be actuated; a pivot interconnecting the contiguous ends of the rod components; means for locking the rod against collapse in its normal extended condition including a bolt which is conned to longitudinal sliding movementl onone of said components and Which is adapted to engage a socket in the other component, and a spring operative upon the bolt to yieldingly hold it engaged in the socket and means associated with one of said components for automatically holding the bolt retracted when the rod is collapsed, and for controlling the bolt to cause it to automatically relock the components when the latter are brought into alignment from collapsed condition.

5. A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends for connection respectively to an actuator and to an element to be actuated; a pivot interconnecting the contiguous ends of the rod com ponents; means for locking the rod against collapse in its normal extended condition including a bolt which is conned to longitudinal sliding movement in an axial cavity in one of the components and which is adapted to engage an axial socket in the other component and means associated with one of said components for automatically holding the bolt retracted when the rod is collapsed, and for controlling the bolt to cause it to automatically relock the components when the latter are brought into valignment from collapsed condition.

6. A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends for connection respectively to an actuator and to an element to be actuated; a pivot interconnecting the contiguous ends of the rod components; means for locking the rod against co1- lapse in its normal extended condition including a bolt which is confined to sliding movement in an axial cavity in one of the components and Which is adapted to engage an axial socket in the other component; and means exteriorly of the rod for manipulating the bolt and means -associated with one of said components for automatically holding the bolt retracted When the rod is collapsed, and for controlling the bolt to cause it to automatically relock the components When the latter are brought into alignment from collapsed condition.

7. A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends ior connection respectively to an actuator and to an element to be actuated; a pivot interconnecting the contiguous ends of the rod components; and means for locking the rod against collapse in its normal extended condition including a bolt which is confined to longitudinal sliding movement in an axial cavity in one of the components and which is adapted to engage an axial socket in the other component, and a manipulating collar slidable on the rod and connected to the bolt by a pin extending through the longitudinal slot in the bolt carrying component.

8. A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends for connection respectively to an actuator and to an element to be actuated; a pivot interconnecting the contiguous ends of the rod components; and means for locking the rod against collapse in its normal extended condition, including a bolt which is confined to longitudinal sliding movement in one of the components andwhichis adapted to engage a socket in the other component, and a spring for maintaining the bolt in engagement with the socket; stops respectively on the components for limiting relative angular movement of said components incident to collapsing the rod; and a cam surface on the socketed component at the region of interpivoting adapted to cooperate with the end of the bolt to yieldingly maintain the rod in collapsed condition.

9. A collapsible connecting rod comprising a pair of components which are normally aligned axially and which have pivots at their remote ends for connection respectively to an actuator and to an element to be actuated; a pivot interconnecting the contiguous ends of the rod components; means for locking the rod against co1- lapse in its normal extended condition including a bolt which is coniined to longitudinal sliding' movement in an axial cavity in one of the components and which is adapted to engage an axial socket in the other component, and a spring for maintaining the bolt yieldingly engaged in the socket; means exteriorly of the rod for manipulating the bolt; interengaging stops respectively on the components for limiting the relative angular movement of said components incident to collapsing the rod; and a cam surface on the socketed component at the region of interpivoting adapted to cooperate with the end of the bolt to yieldingly maintain the rod in collapsed condiy tion.

FRANK A. KUCERA. 

